極度の左心室縮症の犬における心下冠状動脈の減少に起因する血液動力学的メカニズム
L Hittinger1, I Mirsky, Y T Shen
1Department of Medicine, Harvard Medical School, Brigham & Women's Hospital, Boston, Mass, USA.
Circulation
|August 15, 1995
まとめ
左室動脈縮 (LVH) の時,心下冠状動脈の貯蔵量が減少することは,単に構造的な変化ではなく,圧縮力などの血液動力学的要因によるものです. LVH犬におけるこれらの力を低下させることで,冠動脈の流れが回復し,この結論を裏付けている.
科学分野:
- 心血管生理学 心血管の生理学
- 心臓高縮症の研究について
- 冠動脈の血流動力学
背景:
- 左心室動脈縮症 (LVH) は,心下動脈冠動脈の貯蔵量が減少した状態で特徴づけられる.
- 基礎となるメカニズムは,血液動力学的か構造的か,まだ議論されている.
研究 の 目的:
- 血液動力学的または構造的要因が,主として,LVHにおける心下動脈冠動脈の減少に責任があるかどうかを調査する.
- 変化した壁のストレスの役割と,固有の構造の変化を区別する.
主な方法:
- 大動脈帯を介して誘発されたLVHを持つ10頭の意識のある犬を研究しました.
- アデノシンによる最大に近い血管拡張時に評価された冠動脈の血流と心筋壁のストレス.
- LVH犬のサブグループでLVH壁のストレスを変更するために操作されたプレロード.
主要な成果:
- LVHの犬では,アデノシン注入により,サブエンドカルディアルの血流がより小さく,サブエンドカルディアル/エピカルディアル比率がコントロールと比較してより大きく低下しました.
- LVH犬の血管拡張の間,LVH壁のストレスは上昇し続けました.
- LVH犬のLV壁のストレスを軽減することで,サブエンドカルディア/エピカルディアの比率とサブエンドカルディアの血流が正常化しました.
結論:
- 血液動力学的要因,特に圧縮力は,LVHにおける下腸内循環冠動脈の減少に大きく寄与する.
- 構造的変化だけでは,重度のLVHにおける冠動脈準備量の減少を完全に説明することはできません.
- 血動力学的力を調節することで,LVHにおける冠動脈の流れの準備を回復することができます.
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